Genetic Engineering (TEST 3) Flashcards
Genetic Engineering
alteration of organisms genome using molecular biology
Biotechnology
use of living organisms to create products
What has biotechnology been used for in history?
To make beer, bread, cheese, etc.
What contribution did Craig Ventor make to biotechnology?
He chemically synthesized the genome of Mycoplasm and created a new species, Mycoplasma Laboratorium
How do you do Recombinant DNA and how do you know you have been successful?
Take DNA from 2 sources and cut with a restriction enzyme, add DNA ligase to recombine the strands, use assay to find cells with the recominant DNA
What are the five applications of genetic engineering?
1) Pharma
2) Food production
3) Medical Diagnosis
4) Gene Therapy
5) DNA profiling
Biopharmaceuticals
Pharm products produced using biotechnology
How are animals used in biopharma?
We can now express human genes in non human animals and reap the benefits
How is insulin made?
- By transferring insulin gene to E.Coli and letting it produce the insulin in large quantity!
- The two insulin subunits can be produced as fusion polypeptides, purified and cleaved to release the insulin polypeptides.
What are the problems associated with using bacteria to make pharm material? (2)
1) Bacteria can not process/modify euk proteins
2) Euk. don not fold properly in bacteria
What is the solution to this problem with bacteria in producing pharma products?
Bioreactors: genetically modified eukaryotes that produce human products (using fungus, animals, plants instead of bacteria)
Subunit Vaccines
one or more surface proteins developed by genetic engineering.
Ex) the hepatitis B virus surface protein has been cloned in a yeast expression vector
Edible Vaccines
Developed in food using genetic engineering
good for getting to areas without access to vaccines *not use yet
What are the prolems with edible vaccines?
1) will it be profitable?
2) can we get plants to produce enough?
3) cooking destorys poteins
4) Dosage control
5) resistence to GMO by population
How has genetic engineering been used in herbicides?
In order to kill the weeds and not the plants (using ROUND UP), plants are genetically engineered to be resistent to glycophosphate so that the herbicide only kills the weeds and not the plants
How do you make a genetically modified plant resistant to herbicides?
1) make recombinant vector in agrobacterium
2) Agrobacterium infects plant cells
3) Select resistent cells in herbicide containing medium
4) Regenerate these resistent cells (pick plants producing more EPSP)
What is another way genetically modified plants are used?
Developing INSECT resistance crops (example BT toxin in cotton effectively kills insects
What is the problem with insect resistent plants?
Might kill insects that play a positive role in the environment of the plant
How do you make a transgenic animal? (2 ways)
1) Microinjection of DNA that you want into embryo and then but in surrogate, offspring have gene of interest
2) stem cell approach (more viable)
What are the problems with transgenic animals?
Increasing growth of animals hasn’t been successful (except in salmon)
What is Mastitis
Infection in mammory glands that cost dairy industry a huge amount each year
How did they fix the mastitis problem?
Make transgenic cows with lystophan which protects against infection
How is genetic engineering used in medical diagnosis?
using genetic testing
diagnosing disease PRENATALLY
Amniocentesis
Stick needle in mom to penetrate amniotic cavitiy and use flui to make a diagnosis
Chorionic Villus Sampling
Use fetal portion of placental wall
prp gene
cows that don’t have this gene don’t get mad cow disease so they gentically engineer cows without this gene
Glo Fish
transgenic strain of zebrafish, contain a red fluorescent protein from sea anemones
Non-Invasive Prenatal testing
analyze cell free fetal DNA circulating in mothers blood
Preimplantation Genetic Diagnosis
genetic analysis of embryos created by in vitro fertilization
Allele specific oligonucleotides
Short single stranded fragments of DNA able to fi to the membrane, test hybridization agaisnt the ASO’s to determine the genotype
Gene Therapy
Transplanting normal genes in the place of diseased genes to cure patients
Why has gene therapy been a slow process?
Because there have been trajic deaths in human testing
Severe combined immunodeficiency (SCID)
-hereditary disease which dramatically weakens the immune system.
-Individuals born with SCID are abnormally susceptible to infections, and exposure to pathogens can be fatal.
Example:
David lived at Texas Children’s Hospitals in Houston and Shenandoah, Texas.
He died at age 12 after a bone marrow transplant contaminated with Epstein-Barr virus.
Who is Ashanti? What did she have? Why is she important?
She had autosomal form of SCID. Lack of ADA leads to the accumulation of dATP, which inhibits lymphocyte proliferation. FIRST PERSON treated with gene therapy
What are the steps associated with gene therapy?
1) But a plasmid with the gene into a virus
2) Put some cells in from the person you are working with
3) Viruses infect cells
4) Grow infected cells in a culture
5) Reimplant cells into patient
Retrovirus
single stranded RNA that are reverse transcribed into the host genome.
Adenovirus
are double stranded DNA that also use the host DNA replication machinery but are not reverse transcribed.
Four reasons gene therapy could fail?
1) Integration of virus into target cells requires that they are replicating
2) Patient immune responses to the virus
3) Activation or mutation of essential genes
4) Retroviruses specifically cannot carry DNA sequences larger than 8kb, smaller than many human genes
